Perhaps you should try some spelling variations:
ngan hanh » ngan thanh, ngan hang, ngan danh
thu xang » thu hang, thu bang, thu dang
tu sach » thu sach, te sach, tu cach
cau luc » cau truc, cau phuc
hieu ve » hieu va, hieu van
xang xa » lang xa, mang xa, ang xa
su sach » so sach, vu sach
ca tren » cau tren, cu tren, la tren
vi ca » vit ca, li ca, va ca

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (su sach)) thu xang xa hoi. hieu ve ((coc luc) or (cau luc)) ngan hanh vi ca tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) thu xang xa hoi. hieu ve ((coc luc) OR (cau luc)) ngan hanh vi ca tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) thu xang xa hoi. hieu ve ((coc luc) or (cau luc)) ngan hanh vi ca tren".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) thu xang xa hoi. hieu ve ((coc luc) or (cau luc)) ngan hanh vi ca tren*.